1. Field of the Invention
The present invention relates to power operated doors and, more particularly, to a lock and emergency release system operable to allow manual movement of such doors under emergency conditions.
2. Description of the Prior Art
Sometimes a power operated sliding door must be prevented from opening, because of a flaw in the door. This is normally done using a standard manual locking mechanism which has to be locked and unlocked using a key. In an emergency, the manual locking mechanism has first to be unlocked with the key and then an emergency release handle can be pulled to release the door from its associated door operator so as to allow the door to be subsequently manually displaced to an open position thereof. This system can be very dangerous in the case of an emergency because a key is required to open the door if the same has been previously locked to prevent operation thereof by the door operator. Furthermore, two operations are required to unlock the door, thereby increasing the time required to open the door.
Accordingly, there is a need for a new door emergency release system which is adapted to simultaneously unlock a power operated door and release the same from its associated door operator without the necessity of a key.
It is therefore an aim of the present invention to provide a new lock and emergency release system for a power operated door.
It is also an aim of the present invention to provide such a lock and emergency release system which is adapted to enable a normally power operated door to be manually moved to an open position even when the door has been previously locked against opening by the door operator.
It is a further aim of the present invention to provide a relatively simple and reliable lock and emergency release system.
Therefore, in accordance with the present invention, there is provided a lock and emergency release system for a door normally power operated by a door operator, the system comprising a lock displaceable between an idle position to a functional position in which the door operator is prevented from opening the door, at least one emergency release means manually operable for displacing said lock to said idle position thereof and releasing the door from said door operator, thereby allowing the door to be manually opened.